bsc2010 chapter 8 energy and enzymes

metabolism

total chemical reactions of an organism

metabolic pathway

pathway that begins with a specific molecule and ends with a product, each step being catalyzed by a specific enzyme

anabolic pathway

consume energy by building complex molecules ← simpler molecules via dehydration, protein formation, and “uphill” rxn

catabolic pathway

release energy by breaking down complex molecules → simpler compounds via hydrolysis, cellular respiration, and “downhill” rxn

kinetic

active motion, “motion” measured as temp

potential

stored potential, “position”

first law of thermodynamics

energy cannot be created or destroyed, but it can be transferred or transformed

second law of thermodynamics

entropy always increases, causing chemical rxns to result in products w/ more entropy/disorder and less usable energy (spontaneous)

catabolic

metabolic processes that break down molecules to release energy

anabolic

metabolic processes that build complex molecules from simpler ones, requiring energy

exergonic

spontaneous reaction where energy is released; products have less potential energy than it’s reactants

endergonic

reaction that requires energy to occur, not spontaneous; product has more potential energy than it’s reactants

entropy

change in free energy

delta g

spontaneous

chemical rxns are this if they proceed w/o any continuous external influence and no additional energy is needed

non-spontaneous

chemical rxn needs energy to proceed

dehydration

taking away water

hydrolytic

involving or produced by hydrolysis

reaction rate

greater temperature makes this happen faster

ATP

cellular currency, composed of ribose, adenine, and three phosphate groups, powers cellular processes

energy coupling

cells manage energy resources this way by using exergonic processes to drive an endergonic process, being mediated by ATP; these types of rxns are exergonic

phosphorylation

this is how ATP drives endergonic rxns, transferring phosphate group to reactant

oxidation

loses a proton and has lower potential energy

reduction

gains a proton and has higher potential energy

enzymes

a catalytic protein, do NOT change overall free energy needed for a reaction to proceed BUT they do catalyze rxns by lowering the activation energy needed

substrate

the reacant an enzyme acts on

active site

region on the enzyme where the substrate binds

allosteric site

temp ph

these two factors greatly impact the rate of an enzyme-catalyzed reaction

cofactor

inorganic ions that reversibly interact with enzymes; metal ions

coenzyme

organic molecules that interact with enzymes; electron carriers like NADH and FADH2

competitive enzyme inhibitor

bind to the active site of an enzyme to compete with the substrate

non-competitive enzyme inhibitor

bind to another part of the enzyme to make the enzyme change shape and make the active site less effective

allosteric regulator

used to speed up or slow down enzyme activity

enthalpy

the potential energy of the molecule (heat content)